The present invention relates a method for configuring a virtual network, whereby a virtual network is configured between computers and managed, and a network system.
In computer systems, recently, high-speed network connection becomes an important challenge. In particular, data backup processing between servers requires large-bandwidth data transfer between servers.
As a bandwidth enhancement technique for computer networks, there is a heretofore known technique in which a plurality of network interface cards (hereinafter referred to as NICs) are aggregated into one interface that is virtually assumed as a single interface.
For example, a bonding technique is used in a Linux operating system. Bonding enables an increase in the bandwidth of a network (channel) by assigning communication tasks from a plurality of NICs with different network addresses to another NIC (see, e.g., Thomas Davis, et al. “Ethernet Bonding Driver”.
A link aggregation technique, the 802.3ad standard developed by IEEE is also known. Link aggregation assigns one MAC address to a plurality of NICs which are handled as one virtual port (trunk). Access requests to the MAC address assigned to the trunk are distributed across a plurality of NICs belonging to the trunk and transferred to them (see, e.g., “802.3ad—2000 Local and Metropolitan Area Networks—Part 3” IEEE, 2000) (Non-Patent Document 2).
Also, a technique called PM library is disclosed. In the PM library, an application program delivers a packet to a virtual interface (channel). The packet delivered to the interface is labeled with the source computer's NIC address and the destination computer's NIC address described in a table of the virtual interface and transmitted. At this time, if both the source and destination computers have a plurality of NICs, from among these NICs, a pair of destination and source NICs is selected and the packet is transmitted. In a case that a plurality of packets are transmitted asynchronously, the packets are transmitted in parallel to physical interfaces and the bandwidths of a plurality of NICs can be used at the same time. Thereby, an increase in the bandwidth is achieved. Because explicit source and destination addresses are specified, data is transferred in parallel even in communication between two computers and the bandwidths of a plurality of NICs can be used (see, e.g., Tezuka Hiroshi, Hori Atsushi, Ishikawa Yu “Design and Implementation of Communication Library PM for Workstation Cluster”, Joint Symposium on Parallel Processing JSPP '96, Information Processing Society of Japan, 1996, pp. 41-48) (Non-Patent Document 3).